Increasingly there is a need for effective treatments for nervous systems disorders and neurological deficiencies. Many of these diseases correlate with increasing age due mainly to degenerative changes in the nervous system. Although in-early stages of some diseases, certain systems are rather specifically affected (e.g., cholinergic systems in Alzheimer's Disease and Myasthenia Gravis, the dopaminergic system in Parkinson's Disease, etc.) multiple neurotransmitter systems deficiencies (acetylcholine, dopamine, norepinephrine, serotonin) are generally found at later stages of diseases such as senile dementia, multi-infarct dementia, Huntington's Disease, mental retardation, etc. This explains the generally observed multiple symptomology that includes cognitive, neurological and effective/psychotic components (see Gottfries, Psychopharmacol., 86, 245 (1985)). Deficits in the synthesis and release of acetylcholine in the brain are generally thought to be related to cognitive impairment (see Francis, et al., New England J. Med., 7, 313 (1985)) whereas neurological deficits (e.g. Parkinsonian symptoms) and mood/mental changes may be related to impairment of dopaminergic and serotonergic systems, respectively. Other neurological deficits (e.g., Myasthenia Gravis) are related to cholinergic deficiencies in the peripheral nervous system.
Treatment strategies employed previously encompass vasoactive drugs like vincamine and pentoxifylline; metabolic enhancers like ergoloid mesylates, piracetam, and naftidrofuryl; neurotransmitter precursors like L-DOPA, choline, 5-hydroxytryptamine; transmitter metabolizing enzyme inhibitors such as physostigmine; neuropeptides like adrenocorticotropic hormone and vasopressin-related peptides. Except for L-DOPA treatment for Parkinson's Disease and cholinesterase inhibitor treatment for Myasthenia Gravis, these treatment strategies have generally failed to enhance the residual function of the affected systems by enhancing the stimulus-induced release of neurotransmitters. Theoretically, such an enhancement would improve the signal-to-noise ratio during chemical transmission for information, thereby reducing deficits in processes related to cognition, neurological function and mood regulation.
European Patent Application 311,010 discloses .alpha.,.alpha.-disubstituted aromatics or heteroaromatics of the formula: ##STR2## or a salt thereof, which are useful as cognition enhancers.
U.S. Pat. No. 4,760,083 to Myers, et al. discloses that indolinones of the following formula are useful for treatment of cognitive deficiencies: ##STR3## These references teach the necessity of two heteroaryl groups for activity.
European Patent Application No. 0 415 102 A1 by Effland, et al. describes an invention related to the formula: ##STR4## U.S. Pat. No. 3,595,866 to D. E. Butler describes an invention of the formula: ##STR5## European Patent Application No. 0 347 698 A1 wherein Ting, et al. describes a compound of formula: ##STR6##